1. Field of the Invention
The present invention relates to a mechanism that splits/dispenses a trace amount of a liquid (micro order), and more particularly, to a method that splits/dispenses a reagent by a reagent dispensing nozzle in a luminescence measuring device and a mechanism thereof.
2. Description of the Related Art
In various clinical medicine sites, food factories, medicinal drug manufacturing factories, and basic research sites, an aseptic work environment and predetermined biological cleanliness are required. In an environment where the biological cleanliness is required, the number of microorganisms (the number of viable bacteria) in the air (floating bacteria in the air), the number of falling bacteria, and the number of adhesive bacteria are measured. As a method that measures the number of floating bacteria in the air, it is general to use a sampler of the floating bacteria in the air to collect the floating bacteria by natural falling of the floating bacteria or sucking air of a constant amount in collecting the floating bacteria.
In this method, the floating bacteria are collected on an agar plate and are cultured by an incubator for two or three days, and the number of colonies generated after culturing is used as the number of bacteria. However, in this method, a longtime is needed to culture the viable bacteria.
Meanwhile, as a method that enables measurement of the number of microorganisms in a short time, a method that measures adenosine triphosphate (ATP) corresponding to a component in a cell by a bioluminescence method and converts the number of microorganisms is known.
In the bioluminescence method, a luciferin-luciferase luminescence reaction is used, the ATP amount is calculated from the luminescence amount of light generated by mixing and reacting a luminescence reagent containing substrate luciferin and enzyme luciferase and a sample solution containing the ATP extracted from the cells of the microorganisms, and the number of viable bacteria is calculated on the basis of the ATP amount per viable bacterium. In Japanese Patent Application Laid-Open (JP-A) No. 11-155597, a kit that measures the number of viable bacteria using the luminescence reaction is disclosed.
According to the method that measures the number of viable bacteria using the kit disclosed in JP-A No. 11-155597, a measurement time can be decreased. However, when the viable bacteria of the minute amount are measured, the luminescence amount becomes the minute amount. For this reason, background luminescence is greatly affected by mixing of the remaining ATP or the ATP other than the measurement object, and superior measurement precision cannot be obtained.
Meanwhile, in JP-A No. 2008-249628, a luminescence measuring device that can suppress background luminescence due to viable bacteria adhered to a nozzle to dispense a reagent or a remaining ATP and can quickly measure luminescence with high precision is disclosed.
According to the luminescence measuring device that is disclosed in JP-A No. 2008-249628, even in luminescence measurement where the viable bacteria of the minute amount are measured, it is assumed that the viable bacteria of the minute amount can be quickly measured with high precision. However, when the viable bacteria of the minute amount are measured by the luminescence measuring device, a measurement value may be greatly affected by contamination in the device.